Plethysmographic comparison of breathing pattern in heaves (recurrent airway obstruction) versus experimental bronchoconstriction or hyperpnea in horses.
Abstract: Horses with recurrent airway obstruction (heaves) are described as exhibiting "increased abdominal effort," but it is unknown whether this translates to an effective contribution to ventilation. Objective: We hypothesized that heaves is characterized by asynchrony between rib cage and abdominal motions, and that the abdominal component is the major contributor to ventilation. Methods: The rib cage versus abdominal motion in naturally occurring heaves (n = 15) was compared to controls at rest (n = 7) and during hyperpnea because of lobeline treatment, and the effects of histamine-induced bronchoconstriction in controls (n = 10). Methods: Flow patterns, phase angle (theta) between the rib and abdominal compartments, abdominal (Vabd) contribution to tidal volume (VT), and lung mechanics were measured. Results: Findings unique to the heaves group included the loss of biphasic expiratory flow, severely increased theta with the abdomen consistently lagging behind the rib cage, and a reduced contribution of the abdomen to ventilation. A subgroup of heaves (n = 5) with abdominal paradox showed a significant (P < .05) reduction in tidal volume, and increased respiratory rate. Bronchodilation reduced theta in heaves (P = .06), but theta remained significantly higher after bronchodilation than found in controls. Conclusions: We conclude that breathing pattern in horses with heaves is characterized by severe rib cage/abdominal asynchrony, with the rib cage motion in synchrony with flow, therefore dominating ventilation. In a subset of heaves, the abdominal compartment (diaphragm, abdominal muscles) was completely out of synchrony with flow ("abdominal paradox") despite the clinical appearance of "increased abdominal effort."
Publication Date: 2007-03-07 PubMed ID: 17338167DOI: 10.1892/0891-6640(2007)21[184:pcobpi]2.0.co;2Google Scholar: Lookup
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- Comparative Study
- Journal Article
- Abdominal
- Bronchodilation
- Clinical Findings
- Clinical Pathology
- Clinical Study
- Comparative Study
- Diagnosis
- Disease Diagnosis
- Disease Treatment
- Equine Health
- Flow Cytometry
- Histamine
- Horses
- Lung Health
- Pathophysiology
- Physiology
- Pleistocene
- Recurrent Airway Obstruction
- Respiratory Disease
- Veterinary Medicine
- Veterinary Research
Summary
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The research study investigates and compares breathing patterns among horses suffering from recurrent airway obstruction (heaves) and those under experimental bronchoconstriction or hyperpnea. The study hypothesized that horses with heaves would exhibit a lack of coordination between rib cage and abdominal movements, with the latter having a major impact on ventilation.
Methods:
- The study compared rib cage versus abdominal motion in naturally occurring heaves (n = 15) with controls at rest (n = 7) and during hyperpnea due to lobeline treatment. Another comparison group comprised controls (n = 10) affected by histamine-induced bronchoconstriction.
- Several aspects were measured in the study, including flow patterns, phase angle (theta) between the rib and abdominal compartments, abdominal contribution to tidal volume (VT), and lung mechanics.
Results:
- Unique observations in the heaves group included a loss of biphasic expiratory flow, a significant increase in theta with the abdomen consistently lagging behind the rib cage, and a diminished contribution of the abdomen to ventilation.
- Among a subgroup of heaves (n = 5), an ‘abdominal paradox’ was observed where a significant reduction in tidal volume and an increased respiratory rate were seen.
- While bronchodilation reduced theta in horses with heaves, it remained notably higher than controls even after bronchodilation.
Conclusions:
- The research concluded that the breathing pattern in horses with heaves is characterized by severe asynchrony between rib cage and abdominal movements, with the rib cage motion being in synchrony with flow, therefore dominating ventilation.
- In certain cases of heaves, the ‘abdominal paradox’ was identified where the abdominal compartment, including the diaphragm and abdominal muscles, were completely out of synchrony with flow. This was despite the clinical appearance of ‘increased abdominal effort’.
Cite This Article
APA
Hoffman AM, Oura TJ, Riedelberger KJ, Mazan MR.
(2007).
Plethysmographic comparison of breathing pattern in heaves (recurrent airway obstruction) versus experimental bronchoconstriction or hyperpnea in horses.
J Vet Intern Med, 21(1), 184-192.
https://doi.org/10.1892/0891-6640(2007)21[184:pcobpi]2.0.co;2 Publication
Researcher Affiliations
- Lung Function Testing Laboratory, Department of Clinical Sciences, Tufts University School of Veterinary Medicine, North Grafton, MA, USA. Andrew.hoffman@tufts.edu
MeSH Terms
- Albuterol / therapeutic use
- Animals
- Bronchoconstriction / drug effects
- Bronchoconstriction / physiology
- Bronchodilator Agents / therapeutic use
- Histamine / pharmacology
- Histamine Agents / pharmacology
- Horse Diseases / physiopathology
- Horses / physiology
- Ipratropium / therapeutic use
- Lobeline / pharmacology
- Plethysmography / methods
- Plethysmography / veterinary
- Pulmonary Disease, Chronic Obstructive / physiopathology
- Pulmonary Disease, Chronic Obstructive / veterinary
- Respiration / drug effects
- Respiratory System Agents / pharmacology
Citations
This article has been cited 9 times.- Secombe C, Adler A, Hosgood G, Raisis A, Mosing M. Can bronchoconstriction and bronchodilatation in horses be detected using electrical impedance tomography?. J Vet Intern Med 2021 Jul;35(4):2035-2044.
- Dixon CE, Bedenice D, Mazan MR. Comparison of Flowmetric Plethysmography and Forced Oscillatory Mechanics to Measure Airway Hyperresponsiveness in Horses. Front Vet Sci 2020;7:511023.
- Couetil L, Cardwell JM, Leguillette R, Mazan M, Richard E, Bienzle D, Bullone M, Gerber V, Ivester K, Lavoie JP, Martin J, Moran G, Niedźwiedź A, Pusterla N, Swiderski C. Equine Asthma: Current Understanding and Future Directions. Front Vet Sci 2020;7:450.
- Burnheim K, Hughes KJ, Evans DL, Raidal SL. Reliability of breath by breath spirometry and relative flow-time indices for pulmonary function testing in horses. BMC Vet Res 2016 Nov 28;12(1):268.
- Mazan MR, Lascola K, Bruns SJ, Hoffman AM. Use of a novel one-nostril mask-spacer device to evaluate airway hyperresponsiveness (AHR) in horses after chronic administration of albuterol. Can J Vet Res 2014 Jul;78(3):214-20.
- Pacheco AP, Paradis MR, Hoffman AM, Hermida P, Sanchez A, Nadeau JA, Tufts M, Mazan MR. Age effects on blood gas, spirometry, airway reactivity, and bronchoalveolar lavage fluid cytology in clinically healthy horses. J Vet Intern Med 2014 Mar-Apr;28(2):603-8.
- DeVanna JC, Kornegay JN, Bogan DJ, Bogan JR, Dow JL, Hawkins EC. Respiratory dysfunction in unsedated dogs with golden retriever muscular dystrophy. Neuromuscul Disord 2014 Jan;24(1):63-73.
- Simões J, Tilley P. Decision Making in Severe Equine Asthma-Diagnosis and Monitoring. Animals (Basel) 2023 Dec 16;13(24).
- Byrne DP, Keeshan B, Hosgood G, Adler A, Mosing M. Comparison of electrical impedance tomography and spirometry-based measures of airflow in healthy adult horses. Front Physiol 2023;14:1164646.
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